Felis never commented publicly. But in the next update, they added a line to the changelog: "Fixed a bug where the aircraft would misbehave for unlicensed users. This is not a bug. This is a feature."
Felis had not used standard copy protection. He had embedded a logic bomb: if the main executable was altered, a hidden timer would run for 14 days, then subtly corrupt the flight model. The plane would fly almost perfectly—except at the worst possible moment, like on final approach to Kai Tak. Felis 747 Crack
Viper announced he would crack it. Not for money—but for "the sport." He claimed Felis's protection was "amateurish." Within 72 hours, he posted a patched .xpl file. The thread exploded. Thousands downloaded it. Felis never commented publicly